Silver-Russell Syndrome Cases Research Articles

Pathogenic sequence variant and microdeletion affecting HMGA2 in Silver–Russell syndrome: case reports and literature review

Silver–Russell syndrome (SRS) is a representative imprinting disorder characterized by pre- and postnatal growth failure. We encountered two Japanese SRS cases with a de novo pathogenic frameshift variant of HMGA2 (NM_003483.6:c.138_141delinsCT, p.(Lys46Asnfs*16)) and a de novo ~ 3.4 Mb microdeletion at 12q14.2–q15 involving HMGA2, respectively. Furthermore, we compared clinical features in previously reported patients with various genetic conditions leading to compromised IGF2 expression, i.e., HMGA2 aberrations, PLAG1 aberrations, IGF2 aberrations, and H19/IGF2:IG-DMR epimutations (hypomethylations). The results provide further support for HMGA2 being involved in the development of SRS and imply some characteristic features in patients with HMGA2 aberrations.

Short Stature Syndromes: Case Series from India.

Syndromes causing short stature include Noonan syndrome (NS), Williams syndrome, and Silver-Russell syndrome (SRS). SRS is a primordial dwarfism with genetic heterogeneity. The SRS children present with prenatal growth retardation, neonatal hypoglycemia, feeding difficulties, physical asymmetry, with scoliosis and cardiac defect in some cases. The incidence is up to 1 in 100,000. Uniparental disomy, methylation abnormalities, and variants in some genes have been found underlying such phenotype. Growth hormone therapy has been used to improve the height gain in these patients. NS has genetic heterogeneity and most patients present with short stature with or without cardiac defect. Multiple genetic variants, mostly autosomal dominant, contribute to the phenotype. With the availability of next-generation sequencing, more and more genetic disorders causing short stature are being identified in different ethnic populations like Kabuki syndrome and Nance-Horan syndrome. Here, we present some cases of SRS and other additional syndromes with dysmorphism seen in past 5 years.

Prenatal correction of IGF2 to rescue the growth phenotypes in mouse models of Beckwith-Wiedemann and Silver-Russell syndromes

SUMMARYBeckwith-Wiedemann syndrome (BWS) and Silver-Russell syndrome (SRS) are imprinting disorders manifesting as aberrant fetal growth and severe postnatal-growth-related complications. Based on the insulator model, one-third of BWS cases and two-thirds of SRS cases are consistent with misexpression of insulin-like growth factor 2 (IGF2), an important facilitator of fetal growth. We propose that the IGF2-dependent BWS and SRS cases can be identified by prenatal diagnosis and can be prevented by prenatal intervention targeting IGF2. We test this hypothesis using our mouse models of IGF2-dependent BWS and SRS. We find that genetically normalizing IGF2 levels in a double rescue experiment corrects the fetal overgrowth phenotype in the BWS model and the growth retardation in the SRS model. In addition, we pharmacologically rescue the BWS growth phenotype by reducing IGF2 signaling during late gestation. This animal study encourages clinical investigations to target IGF2 for prenatal diagnosis and prenatal prevention in human BWS and SRS.

A retrospective analysis of the prevalence of imprinting disorders in Estonia from 1998 to 2016.

Imprinting disorders (ImpDis) represent a small group of rare congenital diseases primarily affecting growth, development, and the hormonal and metabolic systems. The aim of present study was to identify the prevalence of the ImpDis in Estonia, to describe trends in the live birth prevalence of these disorders between 1998 and 2016, and to compare the results with previously published data. We retrospectively reviewed the records of all Estonian patients since 1998 with both molecularly and clinically diagnosed ImpDis. A prospective study was also conducted, in which all patients with clinical suspicion for an ImpDis were molecularly analyzed. Eighty-seven individuals with ImpDis were identified. Twenty-seven (31%) of them had Prader-Willi syndrome (PWS), 15 (17%) had Angelman syndrome (AS), 15 (17%) had Silver-Russell syndrome (SRS), 12 (14%) had Beckwith-Wiedemann syndrome (BWS), 10 (11%) had pseudo- or pseudopseudohypoparathyroidism, four had central precocious puberty, two had Temple syndrome, one had transient neonatal diabetes mellitus, and one had myoclonus-dystonia syndrome. One third of SRS and BWS cases fulfilled the diagnostic criteria for these disorders, but tested negative for genetic abnormalities. Seventy-six individuals were alive as of January 1, 2018, indicating the total prevalence of ImpDis in Estonia is 5.8/100,000 (95% CI 4.6/100,000-7.2/100,000). The minimum live birth prevalence of all ImpDis in Estonia in 2004-2016 was 1/3,462, PWS 1/13,599, AS 1/27,198, BWS 1/21,154, SRS 1/15,866, and PHP/PPHP 1/27,198. Our results are only partially consistent with previously published data. The worldwide prevalence of SRS and GNAS-gene-related ImpDis is likely underestimated and may be at least three times higher than expected.

A case of Silver-Russell syndrome with hemangioma…a new syndrome or just an association

Silver Russell syndrome is a heterogeneous disorder universally characterized by short stature and asymmetric body habitus Most cases of Silver Russel syndrome are sporadic with no history of the disorder in their family Vascular malformation is not described as a part of the syndrome in any of the existing literature even in standard text books So presence of venous hemangioma with Silver Russel syndrome phenotype can be proposed as new syndrome or just an association

A case report and review of the literature indicate that HMGA2 should be added as a disease gene for Silver-Russell syndrome

Patients with Silver-Russell syndrome (SRS), a syndromic growth retardation syndrome, usually harbor an epimutation at chromosome 11p15 or a maternal uniparental disomy of chromosome 7. However, to date the genetic cause remains unknown in around 40% of SRS cases, suggesting genetic heterogeneity and involvement of other genes.We present a 4-year-old female patient with the clinical diagnosis of SRS and negative results in common genetic SRS diagnostics. Whole exome sequencing identified a de novo heterozygous 7.3 kb deletion on chromosome 12q14.3 including exon 1 and 2 of HMGA2.HMGA2 encodes an architectural transcription factor and has already been linked to body size variations in various genome-wide association studies and mouse models. Reviewing the literature, we found additional four patients with a phenotype of SRS harboring point mutations or structural variants involving HMGA2. We conclude that genetic testing of HMGA2 should be considered in routine diagnostics in patients with the suspicion of SRS.

Hypomethylation of HOXA4 promoter is common in Silver-Russell syndrome and growth restriction and associates with stature in healthy children

Silver-Russell syndrome (SRS) is a growth retardation syndrome in which loss of methylation on chromosome 11p15 (11p15 LOM) and maternal uniparental disomy for chromosome 7 [UPD(7)mat] explain 20–60% and 10% of the syndrome, respectively. To search for a molecular cause for the remaining SRS cases, and to find a possible common epigenetic change, we studied DNA methylation pattern of more than 450 000 CpG sites in 44 SRS patients. Common to all three SRS subgroups, we found a hypomethylated region at the promoter region of HOXA4 in 55% of the patients. We then tested 39 patients with severe growth restriction of unknown etiology, and found hypomethylation of HOXA4 in 44% of the patients. Finally, we found that methylation at multiple CpG sites in the HOXA4 promoter region was associated with height in a cohort of 227 healthy children, suggesting that HOXA4 may play a role in regulating human growth by epigenetic mechanisms.

Genetic disruption of the oncogenic HMGA2\u2013PLAG1\u2013IGF2 pathway causes fetal growth restriction

PurposeFetal growth is a complex process involving maternal, placental and fetal factors. The etiology of fetal growth retardation remains unknown in many cases. The aim of this study is to identify novel human mutations and genes related to Silver–Russell syndrome (SRS), a syndromic form of fetal growth retardation, usually caused by epigenetic downregulation of the potent fetal growth factor IGF2.MethodsWhole-exome sequencing was carried out on members of an SRS familial case. The candidate gene from the familial case and two other genes were screened by targeted high-throughput sequencing in a large cohort of suspected SRS patients. Functional experiments were then used to link these genes into a regulatory pathway.ResultsWe report the first mutations of the PLAG1 gene in humans, as well as new mutations in HMGA2 and IGF2 in six sporadic and/or familial cases of SRS. We demonstrate that HMGA2 regulates IGF2 expression through PLAG1 and in a PLAG1-independent manner.ConclusionGenetic defects of the HMGA2–PLAG1–IGF2 pathway can lead to fetal and postnatal growth restriction, highlighting the role of this oncogenic pathway in the fine regulation of physiological fetal/postnatal growth. This work defines new genetic causes of SRS, important for genetic counseling.

11p15 ICR1 Partial Deletions Associated with IGF2/H19 DMR Hypomethylation and Silver-Russell Syndrome.

The 11p15 region harbors the IGF2/H19 imprinted domain, implicated in fetal and postnatal growth. Silver-Russell syndrome (SRS) is characterized by fetal and postnatal growth failure, and is caused principally by hypomethylation of the 11p15 imprinting control region 1 (ICR1). However, the mechanisms leading to ICR1 hypomethylation remain unknown. Maternally inherited genetic defects affecting the ICR1 domain have been associated with ICR1 hypermethylation and Beckwith-Wiedemann syndrome (an overgrowth syndrome, the clinical and molecular mirror of SRS), and paternal deletions of IGF2 enhancers have been detected in four SRS patients. However, no paternal deletions of ICR1 have ever been associated with hypomethylation of the IGF2/H19 domain in SRS. We screened for new genetic defects within the ICR1 in a cohort of 234 SRS patients with hypomethylated IGF2/H19 domain. We report deletions close to the boundaries of ICR1 on the paternal allele in one familial and two sporadic cases of SRS with ICR1 hypomethylation. These deletions are associated with hypomethylation of the remaining CBS, and decreased IGF2 expression. These results suggest that these regions are most likely required to maintain methylation after fertilization. We estimate these anomalies to occur in about 1% of SRS cases with ICR1 hypomethylation.

Report and review of described associations of Mayer-Rokitansky-Küster-Hauser syndrome and Silver-Russell syndrome.

Silver-Russell syndrome (SRS) and Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome are described in isolation. However, their co-occurrence has only been rarely reported. Here, we present a case report of an adolescent with SRS who was diagnosed with MRKH during the evaluation of primary amenorrhoea. Multiplex ligation-dependent probe amplification analysis showed a normal methylation pattern and normal dosage at 11p15.5. A PubMed search for all peer-reviewed publications (original articles and reviews) using the key words Silver-Russell syndrome, Mayer-Rokitansky-Küster-Hauser syndrome, genetics, hypomethylation and reproductive anomalies identified three cases of SRS with MRKH, two of which were associated with significant hypomethylation of the H19 imprinting control region of the 11p15.5 locus. This report highlights the association between SRS and MRKH. The absence of hypomethylation and normal dosage at 11p15.5 suggests these two rare entities share alternative aetiopathogenic mechanisms.

Clinical characteristics and chromosome 11p15 imprinting analysis of Silver-Russell syndrome - a Chinese experience.

Silver-Russell syndrome (SRS) is an imprinting defect disease. This is the first study of Chinese children with SRS caused by chromosome 11p15 imprinting defects. Twenty-five SRS cases, diagnosed in Beijing Children's Hospital from 2006 to 2012, were studied retrospectively to detect chromosome 11p15 imprinting defects. Over 80% of the children had (i) small for gestational age and postnatal growth retardation (mean height standard deviation score [HT SDS] was -3.56), (ii) mean body mass index (BMI) SDS was -2.10, and (iii) skeletal malformation. Chromosome 11p15 imprinting defects were examined in 16 of the 25 patients. Six had hypomethylation in chromosome 11p15 imprinting control region 1 (ICR1) of the paternal allele; one had hypomethylation in chromosome 11p15 ICR1 and hypermethylation in imprinting control region 2 (ICR2). Another patient had a duplicated maternal chromosome 11p15 fragment. Six patients had been treated with for 3-24 months. Growth rates ranged from 4 to 10.8 cm/year. This study demonstrated that Chinese children with SRS had more growth retardation than bone retardation, severely low levels of BMI, triangular faces, and limb asymmetry. Chromosome 11p15 imprinting defects contributed to 50% of these cases, and ICR1 hypomethylation was associated with asymmetry.

The clinical and molecular genetic study of 20 Silver Russell Syndrome cases

Methods 20 SRS cases diagnosed in Beijing Children’s Hospital from 2006 to 2011 were studied retrospectively for clinical manifestations, physical signs, laboratory examinations and respond of GH treatment. We compared with 3 different diagnostic criteria and used the methylationspecific multiplex ligation dependent probe amplification (MS-MLPA) method to detect the chromosome 11p15 imprinting defects in 16 patients of them, meanwhile take 10 normal control.

Silver–Russell syndrome due to paternal H19/IGF2 hypomethylation in a twin girl born after in vitro fertilization

Silver–Russell syndrome (SRS) is a clinically and genetically heterogeneous syndrome characterized by severe intrauterine and postnatal growth retardation, facial dysmorphism and body asymmetry. One of the main molecular mechanisms leading to the syndrome involves methylation abnormalities of chromosome 11p15. In the last decades, an increase of imprinting disorders have been reported in children born from assisted reproductive technology (ART); however there is currently little evidence linking SRS and ART. Only few infants with SRS born using ART, supported by molecular analysis, have been described. We report on a twin-girl conceived using intracytoplasmic sperm injection (ICSI) diagnosed with SRS. Molecular studies revealed a hypomethylation of the paternal H19/IGF2 Imprinting Control Region. Her twin sister had a normal prenatal and postnatal growth and a normal methylation pattern of the chromosome 11p15. This is the second reported case of a twin infant with SRS conceived using ART with hypomethylation of H19/IGF2; it provides additional evidence of a possible relationship between ART procedures and methylation defects observed in SRS. Given the clinical heterogeneity of SRS, and the increased risk of multiple and preterm births in the ART-conceived children, it is possible that a number of cases of SRS remains undiagnosed in this population. Future studies should investigate the possible link between ART and SRS, in order to better understand the causes of epimutations in ART pregnancies, and to help clinicians to adequately counsel parents who approach to ART and to assess the opportunity of a long-term follow-up of children conceived using ART. © 2013 Wiley Periodicals, Inc.

Beckwith–Wiedemann and Silver–Russell syndromes: opposite developmental imbalances in imprinted regulators of placental function and embryonic growth

Beckwith-Wiedemann syndrome (BWS) and Silver-Russell syndrome (SRS) are two congenital disorders with opposite outcomes on fetal growth, overgrowth and growth restriction, respectively. Although both disorders are heterogeneous, most cases of BWS and SRS are associated with opposite epigenetic or genetic abnormalities on 11p15.5 leading to opposite imbalances in the expression levels of imprinted genes. In this article, we review evidence implicating these genes in the developmental regulation of embryonic growth and placental function in mouse models. The emerging picture suggests that both SRS and BWS can be caused by the simultaneous and opposite deregulation of two groups of imprinted genes on 11p15.5. A detailed description of the phenotypic abnormalities associated with each syndrome must take into consideration the developmental functions of each gene involved.

Silver: Russell syndrome with cryptorchidism

Sir, An 8-year-old boy was admitted for evaluation of bilateral undescended testes and short stature. The boy is a product of non-consanguineous marriage and was delivered at term with birth weight of 1.5 kg. The parents noticed a mild facial asymmetry since birth and poorly developed scrotum with absent testicles. After evaluation, the parents were informed that the testicles would descend in the next few months. His motor and mental milestones were normal and he has average scholastic performance. The parents noticed that the child was shorter than peers. Parents denied birth trauma or any similar illness in other family members. Examination revealed severe short stature (100 cm, <3rd centile), height SDS-5, upper/lower segment ratio – 0.9, head circumference – 51 cm and underweight (10 kg, <3rd centile). He had triangular facies [Figure 1a], hemiatrophy, microdontia with caries [Figure 1b], sparse subcutaneous tissue, clinodactyly [Figure 1c] and bilateral cryptorchidism [Figure 1d]. The rest of the systemic examination was normal. He was diagnosed as a case of Silver-Russell syndrome (SRS). It is a heterogenous syndrome characterized by severe intrauterine growth retardation, relative macrocephaly, triangular face, clinodactyly, and skeletal asymmetry.[1] Our patient had all the classical features of the syndrome resulting in the clinical diagnosis of SRS. Figure 1 Clinical photograph Cryptorchidism is reported in only 15% of patients with SRS.[2] Further investigations revealed normal hematological, biochemical, and thyroid functions. His bone age was 6 years and had normal stimulated growth hormone (15 ng/ml) and testosterone (0.68 ng/ml) values. Ultrasonography revealed right testis in the inguinal area and non-visualization of left testis. A diagnostic laparoscopy found atrophic left testis in the abdominal cavity and the same was removed with correction of the right testis location. The parents were counselled regarding the need of growth hormone therapy. SRS is associated with the genetic imprinting errors on centers situated on chromosomes 7 and 11p15. Maternal uniparental disomy of chromosome 7 is seen in about 10% of cases and hypomethylation of IGF2/H19 locus on 11p15 is seen in 60% of cases.[3] There exists a strong correlation between the clinical phenotype and the extent of hypomethylation. Extremely hypomethylated patients present with congenital aplasia of the uterus and vagina in females and cryptorchidism or testicular agenesis in males.[4] Our patient had bilateral cryptorchidism suggesting a severe methylation defect in 11p15 locus. The severe growth retardation in SRS is due to lower IGF-II, growth hormone GH deficiency, disordered GH axis and H19 hypomethylation. The growth retardation in our patient could be due to lack of downstream signaling molecules of growth hormone. Our patient had normal stimulated growth hormone (15 ng/mL) level and hence the defect could be due to low IGF II and H19 hypomethylation. The exact cause of short stature could not be ascertained due to lack of facilities in our laboratory.

A rare case of Silver-Russell syndrome associated with growth hormone deficiency and urogenital abnormalities

Introduction:Silver–Russell syndrome (SRS) is a very rare genetic disorder. This is usually characterized by asymmetry in the size of the two halves or other parts of the body.Background:We are presenting a case of SRS with growth hormone (GH) deficiency and urogenital abnormalities.Case Report:A 15-year-old boy a product of non-consanguineous marriage brought with a history of short stature and poor development of secondary sexual characters. There were no adverse perinatal events, but weighed 1500 g (<3rdcentile) at birth. He had delayed developmental milestones. He has had a poor appetite and feeding difficulties since childhood. On physical examination, he had a broad forehead, triangular facies, and low-set prominent ears. Asymmetry of the face, upper and lower extremities was noted, with hemihypertrophy on the right side. His height was 119 cm (<3rdcentile) and weight was 18 kg which were low (<3rdcentile) as per his age. He was biochemically euthyroid and GH stimulation testing with clonidine (0.15 mg/m2) showed low GH levels at 30′, 60′, and 90′ were 1.7, 1.6, and 1.1ng/ml, respectively. On micturatingcystourethrogram, grade V complex was noted on the right side. Dimercaptosuccinic acid (DMSA) showed normal functioning kidneys. He was started on recombinant GH with a height velocity of 10 cm/year.Conclusion:Urogenital abnormalities are rare but well described anomalies associated with SRS, and all cases have to be screened for them. GH deficiency is not uncommon in SRS, and GH treatment proves to be beneficial.

Silver–Russell syndrome due to maternal uniparental disomy 7 and a familial reciprocal translocation t(7;13)

Silver-Russell syndrome (SRS) is a genetically heterogeneous disorder characterized by intrauterine and postnatal growth retardation, typical facial features and a spectrum of additional features including body and limb asymmetry and clinodactyly. Maternal uniparental disomy for chromosome 7 (upd(7)mat) was shown to occur in 5-10% of patients with SRS. Maternal UPD7 is clinically often associated with mild SRS. Parents of an affected child are given a negligible recurrence risk as all reported cases with upd(7)mat have been sporadic so far. In general, chromosomal rearrangements-like translocations increase the likelihood of uniparental disomy (UPD) for the chromosomes involved. However, SRS as the result of a upd(7)mat in association with an inherited chromosomal translocation involving chromosome 7 has only been reported once before. Here, we describe the second case of SRS with upd(7)mat due to a familial reciprocal translocation t(7;13). This emphasizes the importance of chromosome analysis in SRS patients with upd(7)mat to rule out chromosomal rearrangements despite their rare occurrence as they are of great relevance for genetic counseling of SRS families.

The KCNQ1OT1 imprinting control region and non-coding RNA: new properties derived from the study of Beckwith–Wiedemann syndrome and Silver–Russell syndrome cases

A cluster of imprinted genes at chromosome 11p15.5 is associated with the growth disorders, Silver–Russell syndrome (SRS) and Beckwith–Wiedemann syndrome (BWS). The cluster is divided into two domains with independent imprinting control regions (ICRs). We describe two maternal 11p15.5 microduplications with contrasting phenotypes. The first is an inverted and in cis duplication of the entire 11p15.5 cluster associated with the maintenance of genomic imprinting and with the SRS phenotype. The second is a 160 kb duplication also inverted and in cis, but resulting in the imprinting alteration of the centromeric domain. It includes the centromeric ICR (ICR2) and the most 5′ 20 kb of the non-coding KCNQ1OT1 gene. Its maternal transmission is associated with ICR2 hypomethylation and the BWS phenotype. By excluding epigenetic mosaicism, cell clones analysis indicated that the two closely located ICR2 sequences resulting from the 160 kb duplication carried discordant DNA methylation on the maternal chromosome and supported the hypothesis that the ICR2 sequence is not sufficient for establishing imprinted methylation and some other property, possibly orientation-dependent, is needed. Furthermore, the 1.2 Mb duplication demonstrated that all features are present for correct imprinting at ICR2 when this is duplicated and inverted within the entire cluster. In the individuals maternally inheriting the 160 kb duplication, ICR2 hypomethylation led to the expression of a truncated KCNQ1OT1 transcript and to down-regulation of CDKN1C. We demonstrated by chromatin RNA immunopurification that the KCNQ1OT1 RNA interacts with chromatin through its most 5′ 20 kb sequence, providing a mechanism likely mediating the silencing activity of this long non-coding RNA.

A case of Silver-Russell syndrome (SRS): multiple pituitary hormone deficiency, lack of H19 hypomethylation and favourable growth hormone (GH) treatment response

Hypomethylation of the imprinting control region 1 (ICR1) at the IGF2/H19 locus on 11p15 is linked to Silver-Russell syndrome (SRS) and/or hemihypertrophy. This SRS patient was born in term with weight of 3500 g (50 percentile) and length 48 cm (1 SD below the mean). He was first noticed at the age of 10 years for short stature (114.5 cm, -3.85 SD), relatively normal head circumference, a classic facial phenotype, hemihypertrophy (2.5 cm thinner left arm and leg in comparison to the right, asymmetric face), moderate clinodactyly and striking thinness (BMI of 15.3). At the age of 30, the body asymmetry ameliorated (1 cm thinner left arm and leg than the right), and BMI normalized (20.5 cm). Methylation analysis was performed by bisulphate treatment of DNA samples, radiolabelled PCR amplification, and digestion of the PCR products using restriction enzymes. The patient had normomethylation, and in addition hypopituitarism, with low levels of growth hormone (GH) (provocative testing before the start and after termination of GH treatment), thyroxin, TSH, FSH, LH and testosterone. The GH was given for six years, growth response was satisfactory and he reached an adult height of 166 cm. This is a first report of hypopituitarism in a patient with SRS without H19 hypomethylation. It seems that the lack of hypomethylation in this hypopituitary SRS patient is responsible, at least partly, for the favourable final adult height under GH treatment.

Screening for genomic variants in ZFP57 in Silver-Russell syndrome patients with 11p15 epimutations

Silver-Russell syndrome (SRS) describes a uniform malformation syndrome characterized by intrauterine and postnatal growth restriction and morphological abnormalities including a small triangular face, relative macrocephaly, asymmetry of the head and limbs, and clinodactyly V. In >38% of SRS cases a hypomethylation of the H19/IGF2 DMR in 11p15 can be detected. Recently, ZFP57 mutations have been identified as a cause of hypomethylation of multiple imprinted loci. To determine whether ZFP57 mutations influence the H19/IGF2 DMR we screened 30 SRS patients with 11p15-hypomethylation for mutations within the coding region of this gene. Thereby homozygosity for a novel variant in exon 6 of ZFP57 was detected in one patient. Heterozygosity for this variant was found in the patients' parents as well as in 2.5% of healthy controls. Except this new and probably apathogenic polymorphism and some registered SNPs no further variants were detected. In conclusion, this study does not provide evidence that ZFP57 mutations are the cause of 11p15-hypomethylation in SRS patients and contribute to the aetiology of SRS.